One-pot gold-catalyzed synthesis of 3-silylethynyl indoles from unprotected o-alkynylanilines

• Jonathan P. Brand,
• Clara Chevalley and
• Jérôme Waser

Beilstein J. Org. Chem. 2011, 7, 565–569, doi:10.3762/bjoc.7.65

• Jonathan P. Brand Clara Chevalley Jerome Waser Laboratory of Catalysis and Organic Synthesis, Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCSO, BCH4306, 1015 Lausanne, Switzerland 10.3762/bjoc.7.65 Abstract The Au(III)-catalyzed cyclization of 2-alkynylanilines was combined in a one

• access to 3-silylalkynyl indoles. To the best of our knowledge, this is the first example of a one-pot process combining a Au(III) and a Au(I) catalyst. Findings 2-Alkynylanilines 2 can be efficiently prepared from 2-iodoanilines 4 and terminal alkynes via Sonogashira reaction with Et3N as solvent

• sequential processes using both Au(I) and Au(III) have not yet been reported. AuCl and TIPS-EBX (1) were added when full conversion of the NaAuCl4-catalyzed cyclization was observed. When 2 mol % of NaAuCl4 and 2 mol % AuCl were added, the second step was unsuccessful. However, with 2 mol % of NaAuCl4 and 4

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• silicon-based Lewis acids were used as catalysts (Scheme 26). Chan and co-workers developed an efficient Au(III)-catalyzed FC arylation of cinnamyl alcohols 64 and electron-rich arenes such as 2,6-dimethylphenol 65. The authors found that this transformation can be catalyzed by various transition metals

• and Brønsted acids, including Au(III), Ag(I), In(III), Zn(II), Cu(II) salts or sulfonic acids. AuCl3 was the most reactive and was subsequently used for further studies. With 5 mol% of catalyst and performing the reaction at room temperature, the desired allylated arenes and heteroarenes 66 were

• -catalyzed synthesis of methyleugenol. FC allylation/cyclization reaction yielding substituted chromanes. Synthesis of (all-rac)-α-tocopherol utilizing Lewis- and strong Brønsted-acids. Au(III)-catalyzed cinnamylation of arenes. “Exhaustive” allylation of benzene-1,3,5-triol. Palladium-catalyzed allylation

Gold film- catalysed benzannulation by Microwave- Assisted, Continuous Flow Organic Synthesis (MACOS)

• Gjergji Shore,
• Michael Tsimerman and
• Michael G. Organ

Beilstein J. Org. Chem. 2009, 5, No. 35, doi:10.3762/bjoc.5.35

• (I)X, Au(III)X3, [32][33][34] and Au nanoparticles dispersed on different supports. For Au(III) catalysts, the reaction has been proposed to proceed via the formation of no less than four organogold intermediates and/or complexes (Figure 1). Further, it has been shown computationally by Straub that

• Au(I) and Au(III) can perform both this and related catalytic cycles with similar energy profiles [35]. This blurs the distinction of the two pathways and raises the possibility that the actual active species in these transformations could be either species, providing that the possibility exists for

• , 124.6, 122.2, 51.0, 45.7, 20.4. HRMS calcd. for C29H28N2O2: 436.2151; found 436.2147. Mechanism of Au(III)-catalyzed benzannulation between aromatic carbonyls and alkynes. X-ray analysis of the metal films used in this benzannulation study. Panels a–e are scanning-electron micrographs (SEM) of all films